Oil burning apparatus



y 1, 1941- c. w. user-191.0 arm. 2,247,977

on. BURNING APPARATUS Fiied Jan. 3 1958 2 Sheets-Sheet 1 INVENTORS I CmrencQ wusmosa &Robert E. may,

Y ATTORNEYS y 1, 1941- c. w. uscl-loLn ETAL v 2,247,977

011. BURNING APPARATUS.

Filed m. 3, 1938 2 Sheets-Sheet 2 FiQfb.

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I 7 Y \K ENTORS cxmmwusmom flown 2.3mm, ATTORNEYS Patented July 1, 1941 r Clarence W.

Uschold, Kenmore, and Robert E.

Duffy, Buffalo, N. Y. a Application January 3, 1938, Serial No. 183,014

This invention relates to heating appliances, and more particularly to installations. suitable for burning liquid fuels. In general, the invention relates to a novel oil burning appliance which is adapted to be inserted in the fire box of a furnace, such as a domestic heating furnace,

for converting said furnace into an efllcient oil burning heating unit. The invention'also contemplates improvements in apparatus designed originally as fuel oil heaters.

One object of the present invention is to provide an improved heater structure wherein complete combustion of the fuel is effected before unburned portions of the fuel come into contact with the furnace walls, and whereby transfer of a maximum portion of the developed heat to the heat output elements of. the structure is effected by a combination of heat radiation and convection processes.

Another object of the invention is to provide an oil heater apparatus including means for supplying the fuel and air mixture to the nozzle in an improved and uniformly consistent manner, whereby maximum combustion efficiency is obtained along with maximum quietness of operation and elimination of the possibility of I flare backs.

Another object of the invention is to provide an oil and air mixing apparatus which is capable of being regulated with respect to oil-to-air ratio in an improved and simplified manner.

Another object of the invention is to provide in an oil 'heating apparatus means for automatically regulating the oil-to-air ratio in response to changes in combustion conditions within the combustion chamber of the apparatus in such manner as to procure maximum operating efficiency and quietness of operation.

Another object of the invention is to provide an improved fuel igniting means for oil burning heaters.

Another object a fuel burning apparatus capable of obtaining complete combustion of the fuel input and maximum heat transfer performance; s

These and other objects and advantages will be morefuily hereinafter disclosed in the claim and speciflcationwhich is of only one form of the invention.

In the drawings:

Fig. 1 is a diagrammatic fragmentary plan 'of. an apparatus incorporating the principles of l the invention; Fig. 2 is afragmentary elevation of the apparatus illustrated in Fig. 1;

of the invention is'to provide Fig. 3 is a horizontal section, on -'a larger scale through a portion of the apparatus shown in Fig 1: v

Fig. 4 is a vertical section Fig. 5 is a detailed view on an enlarged scale of a portion of the secondary air intake mechanism of the apparatus.

Fig. 6 is an enlarged view in elevation of the igniter mechanism of the apparatus.

The present invention has been shown in connection with a domestic hot air heating plant, but it is to be understood that this type of heater installation is only to be taken as repretion may have equal application in connection with any other kind of heater device. In the present instance a heater l0 provided with a cylindrically shaped fire box I2 is provided with made of cast iron or ceramic material or the like and having a tangentially-disposed fuel inlet,

portion i8 formed adjacent its closed bottom end 20. A fuel nozzle 22 is arranged to discharge within the inlet port I8 at a point substantially in line with the inner periphery of the combustion hood. I

oAs will be described more completely hereinafter, the nozzle 22 is adapted to discharge a stream of fuel vapor comprising a homogenousmixture ofair and fluid or pulverized solid fuel substance into the interior of the'combustion hood under a relatively low pressure, and insuch manner that the fuel stream is directed against the adjacent inner wall portion of the chamber member It. by which it is given a circular swirling line of motion. The upper end of the chamis provided with shoulder means 24 supporting thereon-a plurality of upstanding hollow fuel dispersing columns 28. The columns 28 are armixture rising within the combustion chamber l6 may gain access to the interiors of the columns 26. The outer'wall portions of the columns 26 are provided with a plurality of relatively smaller outlet ports 30 winch may be arranged in any desired spacedrelationship and of any desired dimensions so as to procure maximum combustion efllciency effects as willbe. described more taken substantially 5 along the line IVIV of Fig. 1;

sentative, and that the principles of the invenber I8 is open, and the marginal edge thereof' ranged in side by side relation and are provided. with intake openings 28 through the inner wall portions thereof, by means of which the gaseous fully hereinafter. A dome shaped cover 34 formed of cast iron or ceramic or other suitable material is disposed upon the upper ends of the columns 28in such manner as to provide lateral supporting means for the columns 28 and a closure for the upper end of the combustion hood; The inner face of the cover 34 is shaped as shown of generally curved contour and is provided with a fiat marginal flange portion 36 which extends substantial distances transversely of the columns 28 both inwardly and outwardly of the line of the columns to provide a pair of annular shoulders or bailie members adjacentthe upper ends of the columns 25 for controlling the flow of burning fuel in the upper portion of the combustion hood.

Thus, a combustion hood is provided compris- -ing an imperforate lower chamber portion for preheating and imparting a circularswirling mo- 7 tion to a mixture of incoming fuel and air, and

an upper combustion portion having foraminated walls, for storing and reflecting-heat of combustion, to the end that the foraminous section becomes incandescent and the complete burning of all of the incoming fuel substances is expedited. The combustion columns 26'thus provide means for insuring complete combustion of all of the fuel substance entering the hood.

The inlet port l8 and the nozzle 22 are so proportioned and arranged as to provide an annular secondary air inlet chamber ill around the nozzle 22. As illustrated in Fig. 5, an extension tub 42 or the inlet port may be provided at its outer end, exteriorly of the heater casing ill, with anadiustable air inlet shutter 44 provided with registerablealr inlet openings 46. A manually operable arm 48 extends laterally from the shutter for adjustable operation thereof, whereby the ratio of air through the as $6 to the fuel moving through the nomle 22 may be regulated at wfll.

An igniter mechanism for starting combustion provided in the form of an electrically resistant element 50 formed of such material as to become incandescent upon the passage of a low-voltage current of electricity therethrough. The element 1. 50 is mounted upon an insulating block 52 cmi bedded within a wall portion of the combustion 1 chamber It at a position directly opposite the line of fuel .dlscharge through the nozzle 22.

Terminal posts 54 extend through the insulating block I2 and provide means for connecting opposite ends of the element 62 in series with con- 1 ductors I6 leading from a source of low voltage electric current (not shown).. A circuit maizeof fuel discharged into the combustion hood is end that the fuel stream striking thereagainst becomes ignited. A time relay or .other'suitable means may be provided in connection with the igniter switch 58 to automatically procure its movement to 'an 'o position after a predetermined lapse of time, so that the element 59.

is only in service as actually required to cause ignition of the fuel during the starting up process. For use in connection with the burning of fuels of the liquid type such as fuel oil, an improved "feed regulating means is provided. As illustrated more particularly in Figs. 1, 2 and 4, a source of fuel such as a feed supply tank 89 may be connected by means of an outlet tube 62 to a float controlled mixer 64 adapted to deliver a supply of uniformly proportioned and mixed oil and air in the form of amist or vapor to the discharge nozzle 22. The mixer comprises generally a constant level oil reservoir and a discharge orifice disposed at a predetermined eleva-- condition. A needle valv 12 isadapted to co'-' operate with an oil inlet port ll to regulate the flow of oil from the supply tank 69 into the in-' terior of the chamber 66 in response to actuation by the float 88. It is apparent that as the supply of oil in the mixer reservoir rises toward the predetermined level limit the floatrises in atcordance therewith-and urges the needle valve upwardly toward a seated position against the port 14 thus shutting oil the further supply of oil to the reservoir until such time as the float it moves downwardly in response tea withdrawal of oil from the reservoir. By meansoi this mechanism therefore a constant head may be maintainedon the oil within the mixer reservoir. An oil outlet orifice in'the form of a small opening 78 in the end of a tubular jet 78 is provided forjoutlet of the oil from themixer reservoir. As illustrated'in Fig. 4, the orifice '16 is positioned at a slightly higher elevation than the indicated line oi'roil level 80, in the mixer let orifice, the oil within the orifice will assume 3 and-break switch 58 is provided for control of the 1 circuit .through the element 5|. ,In accordance with well known principles of the electrical art 1 the switch 58 is preferably arranged to be oper- 1 ated to an "on position by means of a thermo- I stat element responsive to changes in temperature of the air in the room being heated in such manner that when the temperature drops to a predetermined degree, the thermostat will actuate a linkage mechanism which in turn will move the switch to its "on" position, as will be explained more fully hereinafter. The source of fluid-pressure upon the fuel inlet line may also be automatically controlled by means of the room t'emperature responsive thermostat, in-such manner that when the room temperature lowers to a predetermined degree the fuel feed pressure is opened up and the igniting element" is simulthe form of a tubular channel embracing at one l reservoir, so that in the absence of dlflerential pressure conditions upon the all within the outthe levelfoi' the oil within the. reservoir, and hence will not emerge from the orifice.

An outlet duct 8| for themixer is provided in of its ends, in spaced-relation therefrom, the oil jet I8 and communicating at its other end with theinlet port 82 of an atomizing-pump 84 comprising a stator casing member 88 and an eetaneou ly energized to become incandescent to the centrically mounted rotor 88 equipped with extensible vanes in accordance'with conventional fluid pump construction. The discharge port of the pump 84 .is connected directly to the fuel nozzle 22.. A suitable motor 592 for motivating the pump 84 is provided and as explained hereinabove may be automatically controlled by means of a'rocm temperature responsive thermostatelin such manner that the pump operates whenever the room temperature is below a predetermined degree and shuts oil whenever the temperature reaches a predetermined degree.

The mixer outlet duct 8| is provided at its.

lower end with air inlet passages "I through the walls thereof, and an adjustable shutter ill in the form of a tubular casing enveloping the duct Si is "provided with similar openings and is adapted to be axially rotated by means of a laterally extending crank arm ill to regulate the flow of air through the openings" I". It will be apparent that as the rotor revolves the fluid within the pump is-transported from the inlet side toward the outlet port and fresh air to replace, the displaced vapor is drawn through the openings IIII and the duct I and by the oil orifice 16. As is well known in the hydraulic art, such fluid flow around the orifice It creates a pressure diiferential upon opposite sides thereof v and induces flow of oil therethrough. The parts are so proportioned and arranged that under normal pump. operating conditions the fluid flow through the duct 8| is of such nature as to indue a flow of oil'through the orifice in the form of a rapidly moving spray, thus procuring complete dispersion of-the fuel oil in finely divided form in the accompanying primary air stream to the end that the fuel pump is supplied with an oil and air mixture in the form of a vapor or mist. This fuel vapor is propelled through the nozzle 22 by action of the pump and discharged through the outlet oriflce thereof into: the combustion hood As described hereinabove, the flow of fuel vapor through the nozzle 22 induces level of the oil within the reservoir, and thus it is possible to, temporarily increase the'head of the reservoir; oil-to the end that the oil-to-air ratio of the vapor i suing from the noszleis increased. This may be useful in connectionwith the start- :ing up operation to facilitate ignition of the fuel stream. The upper end portion of the combustion hood, being formed of combustion columns 28 described hereinabove, provides means for molding the flow of fuel and air mixture therethrough, and at the same time provides means for insuring adequate fuel ignition temperatures at this point, to the end that a perfectly quiet and complete combustion ofall of the fuel substance delivered-by the app ratus is effected. The fuel inlet openings 28 of the combustioncolumns it being directed angularly with respect to the inner periphery of the hood. divide the fuel stream and divert it into the enlarged interior chambers of the combustion columns from whence it escapes a in subdivided form through the multiple outlet a corresponding flow of secondary air through the inlet openings 48 and the tube 30. I

Thus, means have been provided for supplying the fuel oil toan oil and air mixing device at a constant head and transporting the fuel oil in a flnely vaporized condition to the point of com bustion in combination with two independent sources of adjustable air-to-oil ratio. Thus means have been provided for the introduction of the heater fuel and combustion air into the combustion hood in delicately balanced relation to the end that complete combustion of the availinlet opening is preferably arranged so as to be openings IIL- Thus the heated gases of the fuel stream'follow tortuous but free paths through the combustion columns and during the starting ,up' process the-heat from the ignited flame becomes stored in the material of the combustion columns up to the point when the combustion columns become incandescent and constitute heat reflecting elements. At thisstage the apparatus has assumed the normal operating condition and as explained hereinbefore, the thermostat device H0 automatically reduces the oil-to-primary air ratio and the flame in the combustion hood moves upwardly away from the nozzle 22 to the region of the combustion columns.

region of the combusti n columns. These columns, being heated by the action of heat reflece tion, now function as igniters to provide ternperatures in the region thereof in excess of the temperature required for complete volatilisation and combustion of the fuel substances. Asexplained hereinabove. this feature in combination with the feature of providing a consistently uni- The inlet ports a are nibstantially in. line with automatically actuated to different positions of air intake quantities in response to temperature changes within the combustion hood It. .As illustrated in Figs. 1 and 2, a thermostat element H0 may be arranged adjacent a wall portion of the chamber I! and connected by means of alinkage system H! to the crank arm I of the primary air inlet shutter to reducev the ratio of primary air to oil during the starting up process and to increase-the ratio'of primary air to oil under normal operating conditions, .thus facili-,

tating the starting up process and automatically acquiring maximum combustion efficiency under normal running conditions.

A reservoir flooding means for arbitrarily raising the level of oil withinthe body of the-mixer may be provided in the form of av spring maintained rod mixer casing. By depressing the rod 5, t e float 68 is arbitrarily lowered in relation to t e Iii extending through a wall of the form and properly balanced oil-to-air ratio in the fuel stream insures maximum combustion eiiiciency and complete heat transfer performance. The novel construction of the combustion columns combines utmost quietness of operation with the above described efficiency of operation.

the flow of'fuel in the combustion hood, and the flow of fuel through the columns I! is natural and not subject to accidental reversals upon changesin fluid velocity conditions in the hood.

Thus, flare backs are prevented.

As illustrated in Fig. 6, the igniter is preferably provided in the form of a sig-sag grid elongated in the direction of the fuel discharge from the home I2. By reason of this construction the fuel stream has a relatively long time of contact with the igniting element. and the parts are so shaped that the element presents no substantial obstruction to thereagainst.

Although only one, been described and shown herein it is understood that the invention is not so limited but that various changes can be made therein withoutdeparting from the scope and spirit of the invention claimed. i

The lower portion of the combustion hood\ then becomes a preheat ing and premixing chamber for the fuel vapor and combustion proceeds to take place largely w within the upper port on of the hood in the 3 element the free flow offluid form of the invention has We claim:

A combustion chamber for oil burners comprising a hollow cylindrical body composed of a base section of imperforate wall form and having a.-fuel inlet adjacent the bottom thereof and a i'oraminous refractory section superposed thereon and a top plate superposed upon said refractory section and functioning as an end closure there- :for, said top plate being formed with a dome shaped intermediate section and a marginal edge portion extending radially and outwardly from said refractory section in the form of a flange therearound to provide'baille means for contion.

trolling flow of combustion gases through the wall of said refractory section, said toraminous section being composed of a plurality of upright contiguous hollow tubular members formed of refractory material and having lateral openings through the tube wall portions thereof for allowing flowof combustion gases from the interior of said combustion chamber into the interior of said tube members and then outwardly thereof and under said top plate marginal edge flange por- CLARENGE W. U SCHOLD; ROBERT E. DUFFY. 

